WebSphere Replication Server for z/OS Using Q Replication: High Availability Scenarios for the z/OS Platform

WebSphere Replication Server for z/OS Using Q Replication: High Availability Scenarios for the z/OS Platform

by Nagraj Alur, Steffen Herold, Huey Kim, Makiko Tsuchida, Mark Wiman, Jaime Anaya
Released June 2006
Publisher(s): IBM Redbooks
ISBN: None

Read it now on the O’Reilly learning platform with a 10-day free trial.

O’Reilly members get unlimited access to books, live events, courses curated by job role, and more from O’Reilly and nearly 200 top publishers.

Start your free trial

Book description

This IBM Redbooks publication provides detailed instructions and scripts for managing failover and switchback in a WebSphere Replication Server for z/OS bidirectional Q replication environment for the z/OS platform. A typical business scenario is used to showcase the bidirectional failover/switchback implementation. This book also includes a WebSphere MQ shared disk and WebSphere MQ shared queue high availability scenario for the source system in a Q replication environment involving unidirectional replication. Key considerations in designing and implementing such environments are discussed.

This book is aimed at an audience of IT architects and database administrators (DBAs) responsible for developing high-availability solutions on the z/OS platform.

Please note that the additional material referenced in the text is not available from IBM.

Table of contents

  1. Figures
  2. Tables
  3. Examples
  4. Notices
    1. Trademarks
  5. Preface
    1. The team that wrote this redbook
    2. Become a published author
    3. Comments welcome
  6. Chapter 1: High availability concepts
    1. Introduction
    2. Levels of availability
  7. Chapter 2: WebSphere Replication Server Q replication overview
    1. Q replication overview
      1. Unidirectional replication
      2. Bidirectional replication
      3. Peer-to-peer replication
    2. Q replication processing flow
      1. Initial synchronization of the data at the source and target
      2. Ongoing replication after the initial synchronization (1/2)
      3. Ongoing replication after the initial synchronization (2/2)
    3. Choosing a particular Q replication topology
    4. Latency considerations
      1. Q Capture latency
      2. Q Capture transaction latency
      3. Queue latency
      4. Q Apply latency
      5. End-to-end latency
  8. Chapter 3: Failover and switchback scenarios
    1. Introduction
    2. Business requirement
    3. Rationale for the bidirectional solution
    4. Environment configuration
    5. Failover and switchback considerations
      1. Failover processing considerations
      2. Switchback processing considerations
    6. Controlled failover and switchback
      1. Controlled failover (CF)
      2. Switchback after CF with no data loss (1/3)
      3. Switchback after CF with no data loss (2/3)
      4. Switchback after CF with no data loss (3/3)
    7. Uncontrolled failover (UF) and switchback
      1. Uncontrolled failover (UF)
      2. Option A: Automatically resync primary and secondary servers (1/2)
      3. Option A: Automatically resync primary and secondary servers (2/2)
      4. Option B: Resync primary and reinitialize secondary (1/3)
      5. Option B: Resync primary and reinitialize secondary (2/3)
      6. Option B: Resync primary and reinitialize secondary (3/3)
      7. Option C: Resync secondary and reinitialize primary (1/3)
      8. Option C: Resync secondary and reinitialize primary (2/3)
      9. Option C: Resync secondary and reinitialize primary (3/3)
      10. Option D: Discard primary changes and reinitialize primary (1/2)
      11. Option D: Discard primary changes and reinitialize primary (2/2)
  9. Chapter 4: WebSphere MQ shared queues and unidirectional replication
    1. Introduction
    2. Business requirement
    3. Rationale for the unidirectional solution
    4. Environment configuration
    5. Setup of this environment
      1. STEP SETSHQ1: Set up connectivity between the databases
      2. STEP SETSHQ2: Catalog databases in the Replication Center
      3. STEP SETSHQ3: Create test tables
      4. STEP SETSHQ4: Create Q replication control tables
      5. STEP SETSHQ5: Create replication queue maps
      6. STEP SETSHQ6: Create Q subscriptions for the test tables
      7. STEP SETSHQ7: Set up WebSphere MQ on both servers
      8. STEP SETSHQ8: Start Q Capture and Q Apply on appropriate servers
    6. Test cases
      1. Failover operations with no inflight automatic load in progress (1/4)
      2. Failover operations with no inflight automatic load in progress (2/4)
      3. Failover operations with no inflight automatic load in progress (3/4)
      4. Failover operations with no inflight automatic load in progress (4/4)
      5. Failover operations with inflight automatic load in progress (1/3)
      6. Failover operations with inflight automatic load in progress (2/3)
      7. Failover operations with inflight automatic load in progress (3/3)
  10. Chapter 5: WebSphere MQ shared disk and unidirectional replication
    1. Introduction
    2. Business requirement
    3. Rationale for the unidirectional solution
    4. Environment configuration
    5. Set up of this environment
      1. STEP SETSHDSK1: Set up connectivity between the databases
      2. STEP SETSHDSK2: Catalog databases in the Replication Center
      3. STEP SETSHDSK3: Create the test tables
      4. STEP SETSHDSK4: Create the Q replication control tables
      5. STEP SETSHDSK5: Create the replication queue maps
      6. STEP SETSHDSK6: Create Q subscriptions for the test tables
      7. STEP SETSHDSK7: Set up WebSphere MQ on primary and secondary
      8. STEP SETSHDSK8: Start Q Capture and Q Apply on primary and secondary
    6. Test cases
      1. Failover operations with no inflight automatic load in progress (1/2)
      2. Failover operations with no inflight automatic load in progress (2/2)
      3. Failover operations with inflight automatic load in progress
  11. Appendix A: Summary of code and scripts used in the scenarios
    1. Summary
  12. Appendix B: Exception processing in a bidirectional Q replication environment
    1. Exceptions overview
      1. Conflict considerations
      2. SQL errors considerations
      3. Viewing exceptions in the IBMQREP_EXCEPTIONS table (1/2)
      4. Viewing exceptions in the IBMQREP_EXCEPTIONS table (2/2)
      5. Considerations for conflict detection in high availability scenarios
    2. Sample exceptions in a bidirectional scenario
      1. Exceptions with inserts (1/2)
      2. Exceptions with inserts (2/2)
      3. Exceptions with deletes
      4. Exceptions with updates
    3. Data inconsistencies in an HA bidirectional scenario
      1. Non-referential integrity-related data inconsistency scenarios (1/2)
      2. Non-referential integrity-related data inconsistency scenarios (2/2)
      3. Referential integrity-related data inconsistency scenarios (1/2)
      4. Referential integrity-related data inconsistency scenarios (2/2)
  13. Appendix C: WebSphere shared queues and shared disk overview
    1. WebSphere shared queues overview
    2. WebSphere shared disk overview
    3. Shared queues versus shared disk implementation
  14. Appendix D: Additional material
    1. Locating the Web material
    2. Using the Web material
      1. System requirements for downloading the Web material
      2. How to use the Web material
  15. Related publications
    1. IBM Redbooks
    2. Other publications
    3. Online resources
    4. How to get IBM Redbooks
    5. Help from IBM
  16. Index (1/2)
  17. Index (2/2)
  18. Back cover

Product information

  • Title: WebSphere Replication Server for z/OS Using Q Replication: High Availability Scenarios for the z/OS Platform
  • Author(s): Nagraj Alur, Steffen Herold, Huey Kim, Makiko Tsuchida, Mark Wiman, Jaime Anaya
  • Release date: June 2006
  • Publisher(s): IBM Redbooks
  • ISBN: None